If the agent is set to daemonize but for whatever reason fails to
init the channel, the error message is lost. Worse, the agent
daemonizes needlessly and returns success. For instance:
# qemu-ga -m virtio-serial \
-p /dev/nonexistent_device \
-f /run/qemu-ga.pid \
-t /run \
-d
# echo $?
0
This makes it needlessly hard for init scripts to detect a
failure in qemu-ga startup. Though, they shouldn't pass '-d' in
the first place.
Let's open the channel first and only after that become a daemon.
Related bug: https://bugs.gentoo.org/810628
Signed-off-by: Michal Privoznik <mpriv...@redhat.com>
Reviewed-by: Ján Tomko <jto...@redhat.com>
---
qga/main.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/qga/main.c b/qga/main.c
index 68ea7f275a..35f061b5ea 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -1430,7 +1430,6 @@ static GAState *initialize_agent(GAConfig *config, int
socket_activation)
if (config->daemonize) {
/* delay opening/locking of pidfile till filesystems are unfrozen
*/
s->deferred_options.pid_filepath = config->pid_filepath;
- become_daemon(NULL);
}
if (config->log_filepath) {
/* delay opening the log file till filesystems are unfrozen */
@@ -1438,9 +1437,6 @@ static GAState *initialize_agent(GAConfig *config, int
socket_activation)
}
ga_disable_logging(s);
} else {
- if (config->daemonize) {
- become_daemon(config->pid_filepath);
- }
if (config->log_filepath) {
FILE *log_file = ga_open_logfile(config->log_filepath);
if (!log_file) {
@@ -1487,6 +1483,20 @@ static GAState *initialize_agent(GAConfig *config, int
socket_activation)
ga_apply_command_filters(s);
+ if (!channel_init(s, s->config->method, s->config->channel_path,
+ s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1))
{
+ g_critical("failed to initialize guest agent channel");
+ return NULL;
+ }
+
+ if (config->daemonize) {
+ if (ga_is_frozen(s)) {
+ become_daemon(NULL);
+ } else {
+ become_daemon(config->pid_filepath);
+ }
+ }
+
ga_state = s;
return s;
}
@@ -1513,8 +1523,9 @@ static void cleanup_agent(GAState *s)
static int run_agent_once(GAState *s)
{
- if (!channel_init(s, s->config->method, s->config->channel_path,
- s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1))
{
+ if (!s->channel &&
+ channel_init(s, s->config->method, s->config->channel_path,
+ s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
g_critical("failed to initialize guest agent channel");
return EXIT_FAILURE;
}
@@ -1523,6 +1534,7 @@ static int run_agent_once(GAState *s)
if (s->channel) {
ga_channel_free(s->channel);
+ s->channel = NULL;
}
return EXIT_SUCCESS;
--
2.45.2
